More on huge circuits at Moorabbin/Point Cook
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Naturally with an increased number of aircraft in the circuit the circuit becomes wider. The saftey issue of keeping the circuit tight has been around since the days of operating the tiger moth - lets move on! Modern engines dont just stop instantly and produce zero thrust - unless through fuel starvation. As the engine is failing it will cough and splutter and produce some thrust - allowing you to reach the field. A standard profile/speed circuit is a safer option - if it wasn't then why have airlines all over the world addopted this approach?? Does GA know better!! About the argument of increased flying training costs - using a standard cirucit allows a better appreciation of a standard profile, which leads to a more stable approach, and has been found to be easier for the student (especially when learning the landing phase) - which leads to reduced time to first solo! Lets ask a student whether a rushed, tight and variable circuit is easier?
Fleery, Fleery, Fleery. Thought you'd know better. There's plenty of reasons for an engine to fail. It could throw a piston, break the crankshaft, blow an oil line and seize etc. In any of those cases it's not gonna produce much thrust. Usually you'll walk away from it during the day but not at night. My old flying school used to have a requirement to turn downwind at 800' at night - I used to use it during the day as well. Early ab initio training the student needs more time. After that, it's fair game to keep 'em tight. Who taught you to fly anyway?!
PM me. Cheers mate.
Incidentally, standard ct width on a Jumbo is about 2.5 nm, flying downwind at about 190 kts.
PM me. Cheers mate.
Incidentally, standard ct width on a Jumbo is about 2.5 nm, flying downwind at about 190 kts.
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Direct anywhere, sure an engine could fail in the way you meantioned. Look back at the airport statistics - has this ever happened??
Using the standard circuit you are against, at the furthest point away from the runway (late downwind, turning base position) the 172 is still able to make it back to the field (say late downwind 17L, can still reach 17L). Seeing as all GA aircraft have an aerofoil profile based around the same NACA-6 profile, hence the same lift/drag ratio - how is it that it's so unsafe??
Sure a first time student will go wide on their initial circuits, and as they get more proficient with the workload it tightens up. Our 'standard circuit' often puts us inside other non-company aircraft, and we have to widen as well - do we complain?
Initial circuit students have around 5 hours experience. With this level of experience should we be teaching transient manouvures?? (ie. leveling off in a climbing turn)
Remember MB is a training aerodrome.
Using the standard circuit you are against, at the furthest point away from the runway (late downwind, turning base position) the 172 is still able to make it back to the field (say late downwind 17L, can still reach 17L). Seeing as all GA aircraft have an aerofoil profile based around the same NACA-6 profile, hence the same lift/drag ratio - how is it that it's so unsafe??
Sure a first time student will go wide on their initial circuits, and as they get more proficient with the workload it tightens up. Our 'standard circuit' often puts us inside other non-company aircraft, and we have to widen as well - do we complain?
Initial circuit students have around 5 hours experience. With this level of experience should we be teaching transient manouvures?? (ie. leveling off in a climbing turn)
Remember MB is a training aerodrome.
Most training GA aircraft based off NACA-6 aerofoil profile.
eg if a Tiger Moth used the 6 series section it would still have an L/D only slightly better than a brick.
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Most GA based off NACA-6, or slight derivative of, as NASA did most of the R&D, so saves manufacturers/designers money.
Sure, the overall drag on the aircraft (tiger moth, Pitts Special - both have low lift/drag) will have a great effect. But warrior/C172 etc, overal have around 9-10 L/D, hence similar glide range. In short, if a heavy C172 can make it, a heavy warrior/C152 should as well. If in the Pitts or tiger moth, sure fly closer.
Sure, the overall drag on the aircraft (tiger moth, Pitts Special - both have low lift/drag) will have a great effect. But warrior/C172 etc, overal have around 9-10 L/D, hence similar glide range. In short, if a heavy C172 can make it, a heavy warrior/C152 should as well. If in the Pitts or tiger moth, sure fly closer.
Fleery - as it was your statement on aerofoil sections used in trainers (I assume we're only discussing SE a/c) which prompted my response I'm obliged to pursue this point to the bitter end. From memory:
The Warriors use a 6 series section, as do the the odd Tomahawk, Grumman and Cardinal.
AMDT: there's the GAW-1 in the above list - developed by NASA from knowledge of supercritical sections, it promised fantastic CLMAX and low drag but the designers of little aeroplanes didn't read the fine print - at low Reynolds Numbers its worse than a 23015.
Sections on the aircraft below are not related to the 6 series at all.
Cessnas use a 23 series. The Airtourer at Civil has a 4412/23012. Decathlons have a 1412.
If we count the Pitts as a trainer its got one wing as a 6 series and the other a 4 digit series.
The Warriors use a 6 series section, as do the the odd Tomahawk, Grumman and Cardinal.
AMDT: there's the GAW-1 in the above list - developed by NASA from knowledge of supercritical sections, it promised fantastic CLMAX and low drag but the designers of little aeroplanes didn't read the fine print - at low Reynolds Numbers its worse than a 23015.
Sections on the aircraft below are not related to the 6 series at all.
Cessnas use a 23 series. The Airtourer at Civil has a 4412/23012. Decathlons have a 1412.
If we count the Pitts as a trainer its got one wing as a 6 series and the other a 4 digit series.
Last edited by djpil; 17th Jan 2004 at 04:27.
Fleery, mate. Firstly, as for the statistics, do you have them readily available or can you point me in the right direction?
Secondly, most posters here know far more about the aerofoils than I ever will. That said, your argument about a 172 on late downwind at YMMB being able to reach the threshold is probably fair enough. Let's however transpose that to a similar aircraft at YMBU or YBDG on an early or mid downwind position - at night. See my point? For ab initio circuits in day VMC at a training aerodrome I see no problem with keeping them reasonably wide. After that, the closer the better in a SE A/C - within reason.
Cheers.
Secondly, most posters here know far more about the aerofoils than I ever will. That said, your argument about a 172 on late downwind at YMMB being able to reach the threshold is probably fair enough. Let's however transpose that to a similar aircraft at YMBU or YBDG on an early or mid downwind position - at night. See my point? For ab initio circuits in day VMC at a training aerodrome I see no problem with keeping them reasonably wide. After that, the closer the better in a SE A/C - within reason.
Cheers.
At night? Absolutely!!!! I was in the MB circuit a little while ago at night following a 172 from somewhere who happened to be doing night solo CTS (heaven forbid! 
)
Had to follow this guy around and when he got to 5 miles GPS I genuinely needed to ask if he was remaining in the circuit.
) Had to follow this guy around and when he got to 5 miles GPS I genuinely needed to ask if he was remaining in the circuit.
If in the Pitts or tiger moth, sure fly closer.
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Yeah, isn't the Pitts E/F glide range fun!! Still even with all the wide circuits able to slot in ok. At times have had to join upwind.
5nm is far too far away, especially at night, and far too scary at YMBU.
5nm is far too far away, especially at night, and far too scary at YMBU.
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Seems to me that the possibility of an engine failure has very little to do with the type of circuit flown, because for a great deal of any circuit attempting to reach the runway is a poor option.
I fly closer circuits in a higher performance GA aeroplane than most, and around crosswind I retain the option of a turnback to the reciprocal runway . Even so, from early downwind (where the turnback option is lost) until late downwind (when a glide can be commenced with sufficient runway remaining) there is no chance of getting to the runway and having enough into wind ground roll left. If you remove the turnback option (which of course is not available to student/low experience pilots) then you have a narrow window in the late downwind where your engine can fail and you can still make it to the runway. That window closes at about the base turn point - in my aircraft at least, should the engine stop then, you are outside the bucket and will never make the threshold anyway.
So, why fly close circuits? Training benefit (more cycles/hour); safety (less chance of misidentifying and colliding); training benefit (more difficult = better pilot in the long run).
I'm not having a dig at anyone here, as we all have different circumstances and objectives, but that's how it is where I am.
I fly closer circuits in a higher performance GA aeroplane than most, and around crosswind I retain the option of a turnback to the reciprocal runway . Even so, from early downwind (where the turnback option is lost) until late downwind (when a glide can be commenced with sufficient runway remaining) there is no chance of getting to the runway and having enough into wind ground roll left. If you remove the turnback option (which of course is not available to student/low experience pilots) then you have a narrow window in the late downwind where your engine can fail and you can still make it to the runway. That window closes at about the base turn point - in my aircraft at least, should the engine stop then, you are outside the bucket and will never make the threshold anyway.
So, why fly close circuits? Training benefit (more cycles/hour); safety (less chance of misidentifying and colliding); training benefit (more difficult = better pilot in the long run).
I'm not having a dig at anyone here, as we all have different circumstances and objectives, but that's how it is where I am.
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If you're flying a higher performance aircraft than most the folks in the tower are usually pretty helpful if you want to turn a closer downwind and get in front of someone (traffic permitting).
The thing that really gets me is the 150's that take full flap turning final a couple of miles out and fly the whole leg at 60kts.
And as someone mentioned earlier circuits can get pretty big when you're assymetric after takeoff.
The thing that really gets me is the 150's that take full flap turning final a couple of miles out and fly the whole leg at 60kts.
And as someone mentioned earlier circuits can get pretty big when you're assymetric after takeoff.
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Let 'em do the circuit they want. If it's big it just let's me get out between 'em at night, and I can fit right in between 'em on a straight in approach. Saves me time and fuel anyhow.
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I have recently had some trouble with wide circuits at night at YMMB, but the funny thing is that I fly at the company that everyone is having a go at in this topic! The aircraft involved could not lay-off drift on upwind, had a very wide downwind and an extended downwind! I had to complete an hour of these annoying circuits as I needed the command before my MECIR test two days later.
Just a note on the company that people are having a go at: My flying training has been with many different schools that have been in different states and therefore different airports. When I came to learn at the said flight school I didnt find their circuits at all different to the training circuits that I have completed elsewhere. Weird, hey! The company is the most professional GA organisation that I have been involved with, I said that I have been involved with.
If you want to have a scary session of night circuits, just head to the west. YPJT can be a scary place for night circuits with Asain Airlines school students flying some interesting circuits! Not to talk about the language barrier!
Anyway, I hope that in the future the regulation authority can organise for GA organisations to get trogether and come up with some uniform procedures. I am sure this will happen!
Safe flying
Just a note on the company that people are having a go at: My flying training has been with many different schools that have been in different states and therefore different airports. When I came to learn at the said flight school I didnt find their circuits at all different to the training circuits that I have completed elsewhere. Weird, hey! The company is the most professional GA organisation that I have been involved with, I said that I have been involved with.
If you want to have a scary session of night circuits, just head to the west. YPJT can be a scary place for night circuits with Asain Airlines school students flying some interesting circuits! Not to talk about the language barrier!
Anyway, I hope that in the future the regulation authority can organise for GA organisations to get trogether and come up with some uniform procedures. I am sure this will happen!
Safe flying
The thing that really gets me is the 150's that take full flap turning final a couple of miles out and fly the whole leg at 60kts.
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Hi all,
I've worked for the company that you're accusing for 3 years. Dont know who your sources are for 1.8Nm - ive never seen that writen in the SOP's, nor have I ever taught that.
Fact of the matter is, our standard circuit is USUALLY inside other aircraft, causing us to also go wider. MB is a training airport, lets all give the new students a go.
I've worked for the company that you're accusing for 3 years. Dont know who your sources are for 1.8Nm - ive never seen that writen in the SOP's, nor have I ever taught that.
Fact of the matter is, our standard circuit is USUALLY inside other aircraft, causing us to also go wider. MB is a training airport, lets all give the new students a go.
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Well Fleery...
Perhaps you should be instructing your students better!
Last Wednesday (6 Jan) I was up in a PA28 doing some x/wind circuits on 31R. In the pattern were 3 "brand new" C172's doing circuits. All 3 were on very wide downwinds, and also turned base pretty late.
Even without the 15 - 20 Kt westerly, NOT ONE would have made it back to the field with an engine failure. With the westerly, they'd have been lucky to make boundary road.
NONE of them were pushing into the westerly, giving them a much longer base than crosswind.
(To paraphrase) Fact of the matter is YOUR standard circuit is ALMOST ALWAYS OUTSIDE other aircraft at MB.
DIVOSH
Last Wednesday (6 Jan) I was up in a PA28 doing some x/wind circuits on 31R. In the pattern were 3 "brand new" C172's doing circuits. All 3 were on very wide downwinds, and also turned base pretty late.
Even without the 15 - 20 Kt westerly, NOT ONE would have made it back to the field with an engine failure. With the westerly, they'd have been lucky to make boundary road.
NONE of them were pushing into the westerly, giving them a much longer base than crosswind.
(To paraphrase) Fact of the matter is YOUR standard circuit is ALMOST ALWAYS OUTSIDE other aircraft at MB.
DIVOSH